Large parties and gatherings are once again effectively banned at MIT fraternities, campus officials announced Wednesday afternoon, three days after a woman was injured in a fall from a window at the now suspended Lambda Chi Alpha.

After a year of tight restrictions from the city of Boston, MIT finally gave fraternities its blessing to hold parties last week, just in time for rush. But Boston officials were on MIT’s back again following the incident on Sunday.

The woman who fell, a student not affiliated with MIT, was reportedly “intoxicated,” according to MIT Police logs, which listed the incident as alcohol-related. MIT prohibits alcohol at fraternity events during rush, which began last Saturday.

For now, gatherings of more than 49 people are forbidden at all MIT fraternities, sororities, and independent living groups, according to an email from Robert Ferrara ’67 and Dean Henry Humphreys at MIT’s Division of Student Life.

The announcement came less than a week after the MIT FSILG office and student leadership told fraternities that similar restrictions from 2013 on gatherings at Boston-based MIT fraternities had been lifted.

“Good News!” was the subject line of the email last Thursday from Interfraternity Council President Haldun Anil ’15. “All fraternities across campus will be allowed to have large events during rush and onwards.”

MIT backtracked on that position Wednesday after Boston officials met with MIT.

The FSILG office and student leadership had introduced a new internal MIT policy on social events meant to ease the restrictions from 2013 put in place by Boston officials, but it was unclear whether the new MIT policy was ever in line with city regulations, or how an Institute decision was supposed to override city rules.

The Boston Inspectional Services Department did not respond to The Tech’s requests for comment on Thursday.

A spokesman for MIT’s FSILG office and Division of Student Life would not say whether they had coordinated with Boston on the new internal policy. He also would not say why MIT decided on Wednesday to restrict parties and events at all fraternities, sororities, and independent living groups — in Boston, Cambridge, and Brookline — rather than just those in Boston.

Last October, the Boston Licensing Board had revoked the assembly licenses of MIT fraternities in the city after a student fell four stories through a skylight at Phi Sigma Kappa. The board’s move meant that no more people could assemble inside a fraternity house than could live in it.

Anil told The Tech last week that Boston had refused to reinstate the licenses multiple times, indicating it was unlikely to grant them for non-commercial operations.

The city’s cap appeared to be lifted last Thursday when student leaders and the MIT FSILG office introduced a more generous formula for determining house capacities just in time for rush. Anil said the new internal policy, which introduced procedures for event registration and risk management, was a proactive effort to “enforce the safety of social events ourselves,” but had not been reviewed by the city.

The fraternities even received an email from Anil on Aug. 29 listing the “social event assembly number” of each house, reportedly calculated by architect Tom J. Stohlman ’76 under the auspices of MIT. The numbers ranged from 98 to 288.

The Sunday incident at LCA “resurfaced the issue of assembly numbers” at Boston’s Inspectional Services Department, which told MIT officials Wednesday that gatherings of 50 or more people would require special event permits, according to Ferrara and Humphreys.

“If you want to have a party of 50 people or more, you have to get what’s called an assembly occupancy,” Buddy Christopher, commissioner of the Boston Inspectional Services Department, said to the Boston Herald. “The assembly permit is something we take very seriously. We’ve asked for this back in January and we never got anything.”

This seemed at odds with what Humphreys and Ferrara wrote in their email: “Throughout our work with ISD over the last year, MIT expected the processes and procedures under development would respond to the concerns ISD raised about assembly numbers.”

The MIT officials said they would continue to work with the city. They also met Wednesday with leaders of FSILGs, many of which had events for new members and pledges scheduled for this weekend.

The MIT chapter of LCA is now under suspension by both its international organization and MIT. In an email to fraternity leaders Wednesday, Anil said LCA could not rush, extend bids, or promise future bids to students during its “temporary suspension” pending an investigation.

Anil also said that an investigation of the LCA incident would be led by Associate Dean for Student Life Judy Robinson, but that no one from the FSILG office would be involved “[i]n an effort to ensure that the investigation is unbiased.”

According to The Boston Globe, Boston Inspectional Services did not find any building code violations during an inspection of LCA Tuesday morning.

This is an updated version of an article first published online on Thursday.